The purpose of this mixed-methods study was to determine the impact of Riverside Middle Prep's Newcomer Program on academic achievement by using quantitative test scores and a case study design to analyze teacher and student perceptions about the newcomer program. The researchers wanted to determine whether there was a difference between EL students who participated in Riverside Middle Prep's Newcomer Program and EL students who did not participate by analyzing WIDA ACCESS scores. Likewise, the researchers also examined whether there was a difference in reading and math MAP scores between newcomer program completers, non-newcomer ELs, and non-EL students. In addition, the study determined whether there was a difference between newcomer program completers' growth rates on the reading and math MAP assessments when enrolled in general education classes versus the newcomer program. The findings indicated no statistically significant difference in the WIDA ACCESS domain scores between newcomer program completers and non-newcomers ELs. There was a statistically significant difference among newcomer program completers, non-newcomer ELs, and non-ELs among various grade levels on the reading and math MAP assessments. In addition, the math MAP growth rate for newcomer program completers was higher when they were enrolled in the newcomer program. The qualitative data revealed three emergent themes (academic preparedness, social self-confidence, and transition). Within academic preparedness, three subthemes emerged: foundational skills/knowledge, lack of preparedness in science/social studies, and teacher support. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]